Just give him some clones and a little advice. Tell him you've been doing a lot of research and blah blah blah. That is, if he's open to suggestions. If he insists on his way, start a comparison grow (make it a competition) and show him the results. The proof is in the product. If you value your friendship with him then be a friend. Help him out. Everyone is wrong at least once or twice in a lifetime. Cut him some slack. After all, he helped get you started. Just because his advice is bad doesn't mean he's a bad friend.